System and method for transcoding digital content

ABSTRACT

A system and method for transcoding digital content (e.g. web content) by correctly employing one annotation for multiple digital contents. This can efficiently reduce the workloads required for the addition of annotation data during the transcoding process. A transcoding system comprises an annotation database system for storing annotation data to be used for the transcoding of contents, and a transcoder for transcoding the contents based on annotation data stored in the annotation database system. Upon receiving an inquiry from the transcoder, a correlation between elements in the contents and descriptions of the annotation data is checked to select one annotation that can be employed for transcoding the content. The correlation is specifically determined based on XPath information.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a technique for transcodinginformation (e.g. digital content, such as a web page) on a network andfor distributing the transcoded information, and in particular to atranscoding technique based on an annotation prepared for theinformation.

[0003] 2. Description of the Related Art

[0004] When access to certain information on a network is requested by apredetermined terminal device, the desired information can be converted,in accordance with specifications of the terminal device or its useenvironment, to be presented to the terminal device. The conversiontechnique is called “transcoding” technique. For example, to provide webcontent on the Internet, the structure of a web page can be adjusted bytranscoding, thereby permitting the web content to be fitted into thesmall display screen of a portable information terminal, or thestructure can be altered and adapted for use by a speech browser forvoice synthesis.

[0005] Roughly speaking, there are two transcoding methods. One is amethod for which no additional information is employed. The other is amethod using external meta information (annotation). According to thetranscoding method for which no additional information is employed, allweb contents can be transcoded, regardless of the types and contents ofthe web data. However, because the types and contents of web data arenot taken into account, the transcoding accuracy is low. On the otherhand, according to the transcoding method based on annotation data,since an appropriate transcoding method is performed based onannotations that correspond to web contents, the transcoding accuracy ishigh. However, since much labor and high costs are required to inputmeta information for annotation, annotation information cannot be addedto all web contents, and the number of web contents that can betranscoded is limited. Therefore, in order to transcode more webcontents at high accuracy, what is important is how workload for addingan annotation should be reduced.

[0006]FIG. 1 is a diagram for explaining the system configuration forperforming transcoding based on annotations. In FIG. 1, a transcodingsystem comprises: a transcoder 910 for converting (transcoding) webcontent; and an annotation database system 920 in which annotation filesused for transcoding is stored. In FIG. 2, when a terminal device 940issues an access request to a web server 930, the web server 930 returnstarget web content to be accessed, and the transcoder 910 receives theweb content first. The transcoder 910 refers to the annotation databasesystem 920, and transcodes the web content based on data, contained inan annotation file (and hereinafter referred to simply as anannotation), that corresponds to the web content. Thereafter, theobtained web content is transmitted by the transcoder 910 to theterminal device 940.

[0007] As a countermeasure for reducing the workload required by thethus arranged system to add an annotation for the transcoding process,it is important that an annotation authoring tool be prepared. Further,one annotation may also be employed for different web contents havingthe same layout. The conventional methods for correlating one annotationwith multiple web contents can be sorted into three types.

[0008] 1. The correlation between URLs (Uniform Resource Locators) andannotations is stored as table data (correlation table data).

[0009] 2. A regular expression of URL is employed.

[0010] 3. An annotation to be employed is dynamically determined byusing a table structure of the web content (an automatic determination).

[0011] As is described above, when conversion using the transcodingtechnique is performed to provide information on a network, thetranscoding method based on annotations is employed in order to attainhigh transcoding accuracy. However, since many workloads and high costsare required for the input of meta information for annotations, atypical network system, such as the Internet, cannot add an annotationto all the information, i.e., all the web contents, and the number ofweb contents that can be transcoded is limited. In order to reduce theworkloads required to add an annotation, the above described method forcorrelating one annotation with multiple web contents has been proposed.However, for the method 1 whereby the correlation between URLs andannotations is stored as table data, it is not practical for the tablecontent to be updated frequently in order to cope with new URLs that aregenerated day after day. Therefore, this method cannot be employedespecially for a web page used for describing news articles or searchresults obtained by a search engine.

[0012] For the method 2 using the regular expression of URL, the authorof an annotation must analyze the URL structure of a web site anddescribe a complicated regular expression, so a great deal of workloadsare required. Further, this method cannot cope with web contents whoselayouts are dynamically changed using cookie data. If the method using aregular expression of URL is employed together with an XPath wildcarddesignating a specific portion of an HTML document, the web contentwhose layout is to be changed dynamically can be coped with to someextent. In this case, overall, the URL structure of the web site isthoroughly analyzed, and a URL condition on which the same layoutappears is determined. And if the web content cannot be handled by theregular expression, the XPath wildcard is employed to provide a wideruse of the method for various purposes.

[0013]FIGS. 2A and 2B are schematic diagrams showing example layouts fora web page on which news articles are described. The layout in FIG. 2Adiffers from the layout in 2B in that a table “Top news” is inserted.The “Top news” table is arbitrarily added or deleted by a person actingas a web content manager. In this case, assume that a regular expressioncan be obtained for a URL that specifies the two web pages in common inFIGS. 2A and 2B, and that the XPath for the web pages is written asfollows.

/html[1]/body[1]/table[7]/tbody[1]/tr[1]/td[3]/table[1]

[0014] If a wildcard is introduced in order to add or delete the “Topnews”, the XPath is written as follows.

/html[1]/body[1]/table[7]/tbody[1]/tr[1]/td[3]/table[starts-with(child::tbody[1]/tr[1]/td[1]/table[1]/tbody[1]/tr[1]/td[1]‘▪Topnews’)]

[0015] However, since these operations are so complicated and thedescription of the XPath also becomes complicated, a lot of workloadsare imposed on the author of the annotation. Furthermore, although themethod for employing the XPath wildcard to change the layout can copewith a simple change, such as the addition or deletion of a visuallysemantic block (a header, a footer, a link list, main text and anadvertisement; hereinafter referred to as a group) that is an element orcomponent of the web content and is represented by a certain layout(e.g. a background color), it is difficult to handle a major changeaffecting the entire layout.

[0016] Further, even for specific web contents at the same URL, thelayout may be dynamically changed based on other web contents that havebeen passed through before the specific web contents are reached.Similarly, the layout may be dynamically changed by re-loading the webcontent using the same URL. In these cases, to add an annotation, usingthe regular expression of URL is not sufficient to handle them, and theXPath wildcard must be employed. However, when there is a major changein the layout, it is difficult for such change to be handled with by theXPath In addition, there are many web pages on which the resultsobtained by a search engine are displayed. The layout of such pagestends to be changed greatly, depending on whether a search target (apage, a product, a book, etc.) corresponding to a matched keyword ispresent or not. In this case it is also difficult to cope with the webpages by traditional way of using the regular expression of URL and theXPath.

[0017] Furthermore, in the method 3 for correlating one annotation withmultiple web contents by employing the table structure of web contentsto dynamically determine which annotation is to be used, the table usedfor specifying a layout is employed as criteria (references) fordetermination. Thus, an appropriate annotation cannot be determined whena table in a web content is not used for a layout purpose, or when alayout having the same form but different content is employed. If thedetermination criteria is more strictly applied in order to avoid anerroneous determination (e.g. different layouts are regarded as beingthe same), layouts that are basically the same may be judged to bedifferent and an erroneous determination could not be avoided.

[0018] It is, therefore, one object of the present invention tocorrectly employ an annotation for multiple web contents and to thusefficiently reduce the workloads required for adding an annotationduring the transcoding process.

[0019] It is another object of the present invention to provide a toolfor simplifying the addition of an annotation to web content.

SUMMARY OF THE INVENTION

[0020] According to the present invention, a system is provided wherein,during the transcoding process, an appropriate annotation is selectedfrom among annotations stored in an annotation database, so that theannotation can be correctly employed for multiple web contents.

[0021] To achieve this object, according to the present invention, asystem for transcoding digital content is provided. The systemcomprises: a database system for storing annotations to be used in atranscoding process; and a transcoder for transcoding the digitalcontent based on an annotation stored in the database. The databasesystem selects the annotation based on correlation between elements inthe digital content and descriptions of the annotations. The systemdescriptions of the annotations may include descriptions for specifyingcertain portions of digital contents, which is typically “XPath”. If aplurality of annotations that can be applied to the digital content arefound, the database system may select the annotation that includes thedescriptions of as many elements in the digital contents as possible.

[0022] Furthermore, the present invention can be implemented byproviding, for the web server, the function of the above describedtranscoding system. Specifically, a web server comprises: contentsstorage means for storing contents; annotation file storage means forstoring annotations; transcoding means for employing correlation betweenthe layout of elements of the contents and the descriptions of theannotations to obtain an annotation that can be employed for thecontents to be processed, and for transcoding the contents; andtransmission means for transmitting contents obtained by thetranscoding.

[0023] According to the present invention, a method for transcodingdigital content is also provided. This method comprises the steps of:obtaining the digital content; reading annotations to be used in atranscoding step from a database; determining an annotationcorresponding to the digital content based on correlation betweenelements in the digital content and descriptions of the annotations; andtranscoding the digital content based on the annotation determined atthe determining step. The descriptions of the annotations may includedescriptions for specifying certain portions of digital contents, whichis typically “XPath”. The invention can also be implemented by a programproduct executable on a computer for performing the above-mentionedmethod of transcoding the digital content. This program product can bedistributed by being stored on a recording medium, such as a magneticdisk, an optical disk or a semiconductor memory, or by being transmittedacross a network.

[0024] According to the present invention, annotation data stored in anannotation database system has the following structure. Annotation datais stored in annotation files that are prepared for units of contents,and includes descriptions for the transcoding process. This data iscorrelated with a layout of elements in the digital contents, typicallyusing XPath. The annotation files are roughly sorted based on locationinformation of the contents on a network, which is typically URLs(Uniform Resource Locators) that are schematically described. Further,the annotation data may include information for identifying an element(optional group) in the digital content for which a layout change isplanned.

[0025] Furthermore, in order to simplify the process for adding anannotation to web contents, an annotation management apparatus orprogram product is provided that serves as a tool for the correlationwith annotations. The apparatus or a program product for managingannotation data to be used for transcoding digital content performs themethod comprising the steps of: evaluating a correlation betweenelements in the digital content and a description in the annotationdata; and presenting a interface to show a state of the correlationbetween the digital content and the annotation data, based on evaluationresults obtained by the evaluating step. The interface may provide, foreach element of the digital content, a list for displaying whether thedescription of a corresponding annotation data is present. Thisinterface also may provide a display component on which a detailedcorrelation between the description of the annotation data and theelements in the digital content is displayed. The interface further mayprovide a display component for accepting an entry from a user andinteractively displaying a state of the annotation data corresponding tothe digital content based on the entry. This interface may provide adisplay component for editing the annotation data.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 (PRIOR ART) is a diagram for explaining an example of asystem configuration that implements transcoding based on an annotation.

[0027]FIG. 2 is a schematic diagram showing an example layout for a webpage that carries a news article.

[0028]FIG. 3 is a diagram for explaining an example of a systemconfiguration according to one embodiment of the invention thatimplements transcoding based on an annotation.

[0029]FIGS. 4A and 4B are diagrams showing an example of XMLdescriptions for an XPath that corresponds to an optional group used forthe embodiment.

[0030]FIG. 5 is a flowchart for explaining an example of the processingperformed by a transcoder.

[0031]FIG. 6 is a flowchart for explaining an example of the processingfor an annotation database according to the embodiment.

[0032]FIG. 7 is a diagram for explaining an example of the functionalarrangement of a site pattern analyzer used for the embodiment.

[0033]FIG. 8 is a diagram showing an example operating screen for theannotation management using the site pattern analyzer.

[0034]FIG. 9 is a flowchart for explaining an example of thesemi-automatic correction processing performed when it is determinedthat multiple annotations can be applied for the same page.

[0035]FIG. 10 is a flowchart for explaining an example of the processingfor adding an annotation to all web contents in a predetermined web siteby using the site pattern analyzer.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

[0036] The preferred embodiment of the present invention will now bedescribed in detail, while referring to the accompanying drawings.

[0037] In order to accurately employ an annotation for multiple digitalcontents, such as web contents, the present invention implements asystem wherein an appropriate annotation is selected from amongannotations stored in an annotation database system, during atranscoding process. Further, in order to simplify the process by whichan annotation is added to web contents, a site pattern analyzer isprovided as an annotation management tool. An explanation will be givenseparately for the system that selects and uses an appropriateannotation at the time of transcoding, and the site pattern analyzer.

[0038]FIG. 3 is a diagram for explaining an example of a systemconfiguration according to the embodiment that performs transcodingbased on an annotation. In FIG. 3, the transcoding system comprises: atranscoder 10 for converting (transcoding) digital contents, such as webcontents; and an annotation database system 20 in which an annotationfile is stored to be used for the transcoding process. The transcoder 10is located between a web server 30 for providing original web contentsand a terminal device (web client) 40 for requesting the web contentsfrom the web server 30. In accordance with the specifications and theenvironment for the terminal device 40, the transcoder 10 transcodes theweb contents downloaded from the web server 30, and transmits thecontents thus obtained to the terminal device 40.

[0039] In this arrangement, the web server 30 is, for example, a servermachine that is implemented by a computer system, such as a workstationor a personal computer. The terminal device 40 can be a computer system,such as a workstation, a personal computer, or an information terminal,such as a PDA (Personal Digital Assistant) or a mobile telephone, and isconnected to the web server 30 by a network.

[0040] The transcoder 10 is a module provided on the network thatconnects the web server 30 and the terminal device 40, and its functionsare carried out by the CPU in a computer system, such as a workstationor a personal computer, that is controlled by a program. The transcoder10 may be provided as an independent computer system that provides aservice for transcoding web contents received from the web server 30, ormay be an added function of a computer system that functions as the webserver 30.

[0041] The annotation database system 20 is implemented by datarecording means, such as a hard disk or a semiconductor memory, and amanagement system that manages the data recording means. The managementsystem can be, for example, the CPU of a computer system, such as aworkstation or a personal computer, that is controlled by a program.Above configuration itself is substantially the same as the conventionaltranscoding system.

[0042] In this embodiment, upon receiving an inquiry from the transcoder10, i.e., during the transcoding of web contents, an annotation that canbe applied to the web contents to be transcoded is selected from amongthe annotation files stored in the annotation database system 20. As aresult, the transcoder 10 transcodes the web contents based on theannotation selected from among the annotation files in the annotationdatabase system 20.

[0043] The annotation file is so selected from the annotation database20 by determining whether the Xpath (description for specifying acertain portion or position of the content) in the pertinent annotationcan be applied to the target web contents, i.e., whether the XPathcorrectly corresponds to a group or an element (a block having a visualmeaning that is represented by a layout, such as a web contentsbackground color, e.g., a header, a footer, a link list, a text, and anadvertisement) in the web contents.

[0044] The annotation files in the annotation database system 20 areroughly sorted by the URLs of the web contents. That is, a schematicURL, e.g. the server name or the folder name of a site where the webcontents to be processed are present, is correlated with each annotationfile. To search for an annotation to be applied to the web contents tobe processed, first, the URL of the web contents is employed as a searchkey, and all the annotations that are correlated with such URL areregarded as candidate annotations for the web contents to be processed.And from among these candidates, an appropriate annotation is selectedbased on the relationship between the above described group (element) inthe web content and the XPath.

[0045] The system in this embodiment supports an optional group that isnot related to the determination process performed to decide whether theannotation can be applied for web contents or not. Specifically, in theweb contents, there is a group such that, even when it is dynamicallymoved, added or deleted, a change in its layout does not greatly affectthe web contents. This optional group is, for example, an advertisementobject, the location of which is changed at random each time the objectis reloaded, or a photographic object in the web contents carrying thenews article. When these groups are regarded as optional groups, whetherthe annotation can be applied or not can be appropriately determined,regardless of the presence/absence or the size of these optional groups,or a change in their locations.

[0046] The optional group can be set by adding “optional attribute” tothe group using the XML description. For example, assume that, inpredetermined web contents, the object for a banner advertisement isdisplayed on one of the following two Xpaths:

/html[1]/body[1]/table[7]/tbody[1]/tr[1]/td[3]/table[1]/tbody[1]/tr[2]/td[1]

/html[1]/body[1]/table[8]/tbody[1]/tr[1]/td[2]

[0047] In these cases, when the optional attribute is added to the twogroups, the advertisement object can be set as an optional object, andcan be excluded from a group for which a determination is to be made asto whether to apply an annotation. FIG. 4A shows an example of the XMLdescription for the XPath in the first case, and FIG. 4B shows anexample of the XML description for the XPath in the second case.

[0048]FIG. 5 is a flowchart for explaining an example operation of hetranscoder 10. While referring to FIG. 3, the transcoder 10 accepts anHTTP request from the terminal device 40 (step 201), and downloads therequested web contents (target HTML) from the web server 30 (step 202).The transcoder 10 then converts the HTML of the obtained web contentsinto a DOM tree (step 203), and employs the DOM tree to issue an inquiryto the annotation database system 20 for an annotation that correspondsto the web contents (step 204).

[0049] When the transcoder 10 receives from the annotation databasesystem 20 an annotation that corresponds to the web contents, thetranscoder 10 first performs a required preprocess for the annotation(step 205). The example of the required preprocess is to exclude theoptional group that does not correspond to the web contents. Thetranscoder 10 converts the DOM tree of the web contents based on theannotation for which the required preprocess has been completed, andinitiates the transcoding operation (step 206). As a result, the objectscan be rearranged for the web contents, or the web contents can bealtered for synthesized voice output. Thereafter, the transcoder 10converts the DOM tree into HTML (step 207), and transmits the transcodedweb contents to the terminal device 40 that originally issued the HTTPrequest (step 208).

[0050]FIG. 6 is a flowchart for explaining an example operation of theannotation database system 20. The operation in the annotation databasesystem 20 to which the transcoder 10 has forwarded an inquiry will nowbe described while referring to FIG. 6. When the inquiry from thetranscoder 10 is accepted by the annotation database system 20 (step301), the URL (Universal Resource Locators) of the web contents isemployed as a key to search for an annotation having a matching resource(step 302). When an annotation having a matching URL is not present, anerror message is returned to the transcoder 10 (steps 303 and 304). Inthis case, either the transcoding for the web contents is not performed,or available transcoding for which an annotation is not employed isperformed.

[0051] If the only one annotation having a matching URL is found in theannotation database system 20, this annotation is transmitted to thetranscoder 10 (steps 303, 305 and 311). If there are multipleannotations having the matching URL in the annotation database system20, an annotation for which all the XPaths match the groups (elements)in the web contents is selected (steps 305 and 306). If the only onesuch annotation is selected in the annotation database system 20, thisannotation is transmitted to the transcoder 10 (steps 307 and 311).

[0052] If multiple annotations are found in which there are matchingXPaths in the annotation database system 20, the annotation whose numberof matched groups (elements) is the greatest is selected and transmittedto the transcoder 10 (steps 307, 308, 309 and 311). If there aremultiple such annotations in the annotation database system 20, thelatest annotation is selected and transmitted to the transcoder 10(steps 309, 310 and 311). Through this processing, an annotationcorresponding to the inquiry issued by the transcoder 10 is elected andis used by the transcoder 10 for the transcoding.

[0053] As is shown in FIG. 6, if an annotation that matches web contentis not present in the annotation database system 20, an errornotification is issued to the transcoder 10. If a plurality ofannotations match with the same web content, the annotation having thegreatest number of matched groups (elements) in the web content, or thelatest annotation is selected. In addition to the above describedmethod, the conventional layout matching technique for determining thesimilarity between the layout of web contents and an assumed layoutbased on an annotation may be employed to determine the similaritybetween the layouts, and an annotation for which the assumed layout isthe most similar may be employed first.

[0054] However, the above described states mean that there arenon-matching annotations. This will occur not only when the addition ofannotations for web contents is not satisfactory, but also when thelayouts for the target web contents are changed after the system hasbeen activated, or when web contents having new layouts are added.Therefore, it is preferable that, even after the system has beenactivated, the correlation between the web contents and the annotationsbe monitored and adjusted as needed.

[0055] As the method for implementing the invention, when a transcodingerror has occurred because web contents do not match any annotations,there are web contents that match multiple annotations, or there are webcontents that are transcoded while there is text information that is notdesignated by a group, notification of the occurrence of the transcodingerror may be transmitted to the terminal device for annotation authoringto inform the author that this state exists (on-the-fly tests). Uponreceiving this notification, the author may employ a tool such as a sitepattern analyzer, which will be described later, or may employ anannotation editor to edit an annotation, so that the state whereinappropriate annotations are correlated with web contents is maintained.

[0056] As is described above, since a check is performed to determinewhether the elements that correspond to all the XPaths included in anannotation are present in web contents to be transcoded, theappropriateness of the annotation is determined by the annotationdatabase system 20. Thus, the layout of the web contents can bedetermined in real time, and an appropriate annotation can be selected.Further, since the layout of the web contents is directly determined,unlike the conventional technique according to which a table structurefor the web contents is referred to when determining an annotation to beused, the annotation can be controlled to prevent an erroneous estimatesuch that different layouts are regarded as being the same, or such thatlike layouts are regarded as being different.

[0057] In the method for managing the annotation file in the annotationdatabase system 20, a URL is employed as the first key when searchingfor a desired annotation, and thereafter, determination of anappropriate annotation depends on the layout of the web contents. Thatis, the annotation candidates to be used are roughly determined byreferring to URLs, and thereafter, the annotation to be used isspecified in accordance with the correlation between the actual layoutof the web contents to be transcoded and the description of theannotation (i.e., the XPaths of the group and the annotation).Therefore, so long as the location of web contents can be roughlydesignated, any URL can be used as a search key and the regularexpression of a restricted URL need not be designated.

[0058] The operation of adding annotations itself differs in no way fromthe conventional operation performed to add an annotation to webcontents. Further, if there is no annotation available for use withpredetermined web contents, instead of using an XPath wildcard to copewith this situation, all that is necessary is for another annotation tobe input that can be used with the web contents. Therefore, theannotation addition process is simplified. And in addition, since anXPath wildcard need not be taken into account, the semi-automaticgeneration of an XPath can be easily performed using the annotationeditor. As is described above, according to the embodiment, the additionand the adjustment of an annotation can be greatly simplified.

[0059] As is described above, according to the embodiment, theannotation is not generalized using an XPath wildcard, but instead, anecessary annotation is added to the layout of desired web contents. Forexample, when the “Top news” table in FIG. 2 is added or deleted, orwhen the layout of the web contents is changed, even with the same URL,an annotation is generated for the individual layouts. Thus, the numberof annotation files required to transcode the same number of webcontents is increased compared with the conventional method according towhich annotations are generalized. However, an adjustment of regularexpression of URL and an XPath, which are complicated operations forwhich maintenance is difficult, can be replaced by a simple operation ofadding an available annotation to web contents for which there is nocorresponding annotation. Thus, operating costs can be reduced, andmaintenance can be simplified.

[0060] The transcoding system (the transcoder 10 and the annotationdatabase system 20) in FIG. 3 for the embodiment is provided separatelyfrom the web server 30. However, in this embodiment, the function of thetranscoding system may be provided for the web server 30. In this case,the web server 30 comprises: web content storage means for storing webcontents; annotation file storage means that corresponds to theannotation database system 20; and web convent transcoding means thatcorresponds to the transcoder 10. Upon receiving a request from a webclient, the web contents obtained by the transcoding means istransmitted via transmission means, such as a network interface.

[0061] Even when the transcoding system of this embodiment, includingthe annotation database system 20, is employed, as is described above,there still has occurred a problem in that it has been determined thatmultiple annotations can be applied for the same web contents, and aproblem in that web contents are found that do not match any annotation.The first case is resolved, during the process performed to examine theannotation database 20, by selecting an annotation having the greatestnumber of matched groups, or by selecting the latest annotation.However, to the extent possible, it is preferable that a singleannotation correspond to each set of web contents. In this embodiment,therefore, a tool, a site pattern analyzer, is provided that manages anannotation and supports the detection and resolution of the aboveproblems.

[0062] The site pattern analyzer is software (a program) for displayingthe tree structure of web contents in a desirable site, and forinteractively presenting the state wherein an annotation is added. Forexample, to perform the annotation management for this embodiment, thesite pattern analyzer may be installed in a computer that implements thetranscoder 10 and the annotation database system 20, and that, as theannotation management apparatus, operates the CPU of the computer thatperforms the annotation management for this embodiment. When the sitepattern analyzer is employed, the annotation author can confirm theannotation addition state while overviewing the desired site in itsentirety, and can either add a new annotation or adjust the currentlyavailable annotation as needed. The site pattern analyzer, which issoftware, can be distributed by being stored on a storage medium, suchas a magnetic disk, an optical disk or a semiconductor memory, or bybeing transmitted across a network.

[0063] Management software of this type has also been studied for theconventional transcoding system that employs the regular expression ofURL and the XPath. However, the following problems remain, and it isdifficult to design practical management software. First, since the unitof an annotation is a group and has a different URL regular expression,it is difficult to present a list of the existing correlations betweenthe annotations and target web contents. Second, since the intergrouprelationships in the web contents are complicated by the XPaths and theregular expression, total management of the groups is difficult. In theembodiment, to resolve the first problem, the annotations are managed bya unit of web contents (a set of groups/elements), so that themanagement of annotations can be visualized using a table. To simplysolve the second problem, simply, the annotations will be managed by theunit of web contents, and for the web contents to which no annotation isadded, a new annotation will be added.

[0064]FIG. 7 is a diagram for explaining an example of the functionalarrangement of a site pattern analyzer. In FIG. 7, a site patternanalyzer 50 provided for this embodiment comprises: a matchingevaluation module 51, a tree view controller 52, an annotationcorrection module 53, a matching character string extraction module 54,and a browser/DOM tree synchronization module 55. These components aresoftware blocks the functions of which are performed by the CPU, whichis controlled by the program in the computer in which the site patternanalyzer 50 is installed. Further, the site pattern analyzer 50 preparesan annotation table 56 and a matching table 57 in the main memory of thecomputer or in the cache memory of the CPU, and employs these tables forthe processing.

[0065] At the time of activation or reloading, the thus arranged sitepattern analyzer 50 travels across the entire site to be managed by anannotation, and employs input means (not shown), such as an interface,to cache the information for the web contents. At this time, the HTMLfile list concerning the web contents is also created. The site that isto be managed can be arbitrarily designated by an author. Further, inconsonance with the same timing, the site pattern analyzer 50 employsinput means (not shown), such as an interface, to read all the data forthe annotation files from the annotation database 20, and stores thedata in the annotation table 56.

[0066] The matching evaluation module 51 receives the HTML file of theweb contents, which are cached as a processing target during the initialoperation, and the HTML file list, and also receives the data for theannotation file (hereinafter referred to as annotation data) from theannotation table 56.

[0067] Then, the matching evaluation module 51 calculates the matchingof the XPath in the annotation and the web contents, and stores thecalculation results (the evaluation results) in the matching table 57.The evaluation results stored in the matching table 57 are displayed asa list for viewing on the operating screen of the site pattern analyzer50, which will be described later. When recalculation is required, e.g.,when the site pattern analyzer 50 is activated or reloaded, the matchingevaluation module 51 is called and performs the required processing.

[0068] The tree view controller 52 receives the HTML file for the webcontents, which are cached as a processing target during the initialoperation, and the HTML file list, and also receives the data for theannotation file from the annotation table 56. The tree view controller52 then displays the tree for the annotations and the web contents forthe entire site that is to be managed. The data output by the tree viewcontroller 52 is displayed as a tree for viewing on the operating screenof the site pattern analyzer 50, which will be described later.

[0069] The annotation correction module 53 controls the changes in theannotation data stored in the annotation table 56 due to the propertychanges or the semi-automatic corrections. And the annotation correctionmodule 53 controls the temporary caching of the annotation changes andthe changes that are reflected by the actual annotations. The matchingcharacter string extraction module 54 reads, from the matching table 57,the evaluation results obtained by the matching evaluation module 51,and receives the DOM tree of the web contents that are cached as aprocessing target during the initial operation. The matching characterstring extraction module 54 then calculates a matching character string,so that the matching details of the XPaths in the annotations and theweb contents are displayed using a character string, or so that an emptygroup, wherein there are no matched annotations, or omitted contents aredisplayed. The processing results obtained by the matching characterstring extraction module 54 are displayed as a detailed view on theoperating screen of the site pattern analyzer 50, which will bedescribed later.

[0070] The browser/DOM tree synchronization module 55 synchronizes a DOMtree consisting of predetermined web contents with the browser view ofthe predetermined web contents. And the data output by the browser/DOMtree synchronization module 55 are displayed as a browser view on theoperating screen of the site pattern analyzer 50, which will bedescribed later.

[0071]FIG. 8 is a diagram showing an example operating screen of thesite pattern analyzer 50 for the annotation management. As is shown inFIG. 8, a tree view 61, a list view 62, a detailed view 63 and a browserview 64 are provided for an operating screen 60.

[0072] The tree view 61 is the output of the tree view controller 52 andindicates the annotations and the tree structure of the web contents forthe entire site that is to be managed. When the author selects a desireddirectory in the tree view 61, the author can designate the directorythat includes the web contents for which the author desires to confirmthe annotation application state.

[0073] The list view 62 indicates, for the web contents included in thedirectory designated in the tree view 61, a list of the evaluationresults that are obtained by the matching evaluation module 51 and thatare stored in the matching table 57.

[0074] The list view 62 includes page titles 62 a and URLs 62 b forspecifying web contents, the ID for specifying corresponding annotation62 c (annotation name), the number of annotations 62 d that match theweb contents, and correlations 62 e (the presence or absence ofcorresponding elements) between the groups(elements) in the web contentsand the descriptions in the annotations. With this list view 62, theauthor can determine for which web contents an annotation should beadjusted or a new one should be added, and can also identify a requiredoperation. In addition, when the author selects desired web contents inthe list view 62, the author can designate the web contents to bedisplayed in the detailed view 63.

[0075] In this embodiment, in the process for matching web contents andan annotation, even when there is an omitted annotation, an annotationthat can be applied for the web contents may be determined, and theremaining contents may not be defined for transcoding (super setproblem). To avoid this problem, an annotation omission indicator stringand an empty group indicator string (62 f) can be provided for eachannotation in the list view 62 in FIG. 8. When the total number ofcharacters in a text node, or the ALT attribute of an image, that is notincluded in an annotation for a group exceeds a predetermined number(designated by a user), the annotation omission indicator string isdisplayed as an alert indicating that there may be an omittedannotation. The empty group indicator string is displayed when thecontents are not included in the group. Since these indicator stringsare displayed, the author of the annotation can easily determine whichannotation should be examined or corrected.

[0076] For these indicator strings, for example, the contents can beconverted into a character string according to the following rules, andthe content volume can be measured.

[0077] 1. Use character string of the normal text node.

[0078] 2. Use character string of the ATL attribute in case of an image.

[0079] 3. Determine as a character string an image file name for animage having no ALT attribute. It should be noted that when an imagefile name, such as spacer.gif or lxlwhite.gif, is listed in advance foran image that can not be regarded as contents, this image file name isexcluded.

[0080] 4. When the number of input characters is obtained in advance bytext-text area input, employ its dummy string (e.g., xxxxxx) as acharacter string. When the input character count is not known, employ acharacter string having an arbitrary number of characters.

[0081] 5. Treat “input” of “image type” in the same manner as is animage.

[0082] 6. When an embedded object is present, allocate an appropriatecharacter string based on the size of the object occupied on the screen.

[0083] 7. When the contents, such as JavaScript, are to be dynamicallygenerated or moved, calculate a character string that does not exceed apredictable range.

[0084] The detailed view 63 is the output of the matching characterstring extraction module 54, and a detailed correlation between thecontents (descriptions) of an annotation and an object (element) in webcontents is displayed as a character string. With this detailed view 63,the author can determine whether the annotation can be correctlycorrelated with an appropriate object in the web contents.

[0085] In the browser view 64, the output of the browser/DOM treesynchronization module 55 is displayed via a browser component, and theoperation using the tree view 61, the list view 62 and the detailed view63 is reflected by the actual web contents. Thus, the author can performthe annotation management, while confirming how the transcoding based onthe annotation is actually reflected by the web contents.

[0086] In addition to the main functions as explained while referring toFIG. 7, a function for semi-automatically adding a condition to theXPath, in accordance with a designation by an author, can be providedfor the site pattern analyzer 50 in this embodiment as a function tocope with when multiple annotations can be applied for the same webpage.

[0087] For example, among the XPaths for the Top news table in FIG. 2,the portion that can easily be generated by the annotation editorreaches the area up to the designation of a table.

/html[1]/body[1]/table[7]/tbody[1]/tr[1]/td[3]/table[1]

[0088] In this case, the annotation must be switched depending onwhether the character string is “▪Top news” or “▪Memo”. Therefore, thefollowing condition must be added.

(starts-with(child::tbody[1]/tr[1]/td[1]/table[1]/tbody[1]/tr[1]/td[1],‘▪Top news’)]″

[0089] For the common annotation editor that performs, as one operationunit, the addition of an annotation to one unit of web contents, it isdifficult to add the above condition. However, since with the sitepattern analyzer 50 multiple web contents can be browsed at the sametime, a necessary condition can be added by a semi-automatic process.

[0090]FIG. 9 is a flowchart for explaining an example of thesemi-automatic process. In FIG. 9, when the process is initiated, first,multiple web contents (e.g., 10 web contents) are displayed that it isdetermined match the same annotation (step 701). An author then refersto the detailed view 63 to select an example (a cell in a table) thatdesignates an incorrect element (step 702), and inputs an “error groupautomatic correction” command (step 703). It should be noted that thiscommand is for the same group. Then, candidates to be corrected arepresented (step 704). These candidates are listed in accordance with thefollowing conditions.

[0091] Examine whether a candidate can be identified by the first ncharacters of a character string in a group.

[0092]  e.g.

/html[1]/body[1]/table[3]

→/html[1]/body[1]/table[3][starts-with(child::*, ‘old article’)]

[0093] Examine whether a candidate can be identified by the backgroundcolor.

/html[1]/body[1]/table[3] [@bgcolor-‘CCCCCC’]

[0094] Search for a node that is included in either one.

/html[1]/body[1]/table[3] [child::tbody]1]/tr[2]/td[1]/img[1]

[0095] Thereafter, the author selects an appropriate candidate to becorrected (step 705). In addition to this candidate selection method, amethod may be mounted for employing a wizard type to perform the processstep by step.

[0096] An explanation will now be given for the processing during whichthe above described site pattern analyzer 50 is employed to add anannotation to all the web contents in the redetermined web site. FIG. 10is a flowchart for explaining the processing. As is shown in FIG. 10,first, the entire desired web site is traversed and the web contents areobtained and cached (step 801). Then, the site pattern analyzer 50 orthe annotation editor is employed to create an annotation for the cachedweb contents (step 802).

[0097] Then, the site pattern analyzer 50 analyzes the web contentscached at step S801 and the annotation created at step 802, and displaysor outputs information concerning which annotation can be applied towhich web contents in the web site (step 803). Subsequently, anannotation is added to the web contents to which it is determined, bythe analysis, that an annotation has not been added (step 804). In theannotation addition process, the annotation editor may be employed toadd a new annotation, or a predetermined group of conventionalannotations may be established as an optional group to be applied fordesired web contents. Further, when multiple web contents are detectedfor which the same annotation is to be applied, a group to which theannotation is erroneously applied is corrected (step 805). For thiscorrection, the semi-automatic correction function explained whilereferring to FIG. 9 can be employed. Through the above processing, whenone annotation can be correlated with each unit of all the web contents(or all the main web contents), the annotation file that is thuscompleted is uploaded to the transcoding system (step 806).

[0098] In the above example, it is assumed that the annotation editorthat is provided separate from the site pattern analyzer 50 is employedfor the creation of an annotation. However, the function of theannotation editor may be provided for the site pattern analyzer 50. Inthis case, when, as will be described later, the annotation omission isdetected for each view that is the output of the site pattern analyzer50, or when an annotation is to be added to the web contents to which noannotation has been added, the annotation editing function of the sitepattern analyzer 50 can be employed to edit an annotation, without anannotation editor being required.

[0099] As is described above, according to the present invention, anannotation can be correctly employed for multiple web contents, and theworkload required for the addition of an annotation due to thetranscoding can be reduced considerably. According to the presentinvention, a tool can be provided for simplifying the operation foradding an annotation to web contents.

What is claimed is:
 1. A system for transcoding digital content, thesystem comprising: a database system for storing annotations to be usedin a transcoding process; and a transcoder for transcoding the digitalcontent based on an annotation stored in the database; wherein, thedatabase system selects the annotation based on correlation betweenelements in the digital content and descriptions of the annotations. 2.The system according to claim 1, wherein said descriptions of theannotations include descriptions for specifying certain portions ofdigital contents.
 3. The system according to claim 2, wherein saiddescriptions for specifying certain portions of the digital contents isXPath.
 4. The system according to claim 1, wherein, if multipleannotations that can be applied to the digital content are found, thedatabase system selects the annotation that includes the descriptions ofas many elements in the digital contents as possible.
 5. A method fortranscoding digital content, the method comprising the steps of:obtaining the digital content; reading annotations to be used in atranscoding step from a database; determining an annotationcorresponding to the digital content based on correlation betweenelements in the digital content and descriptions of the annotations; andtranscoding the digital content based on the annotation determined atthe determining step.
 6. The method according to claim 5, wherein saiddescriptions of the annotations include descriptions for specifyingcertain portions of digital contents.
 7. The method according to claim6, wherein said descriptions for specifying certain portions of thedigital contents is XPath.
 8. A program product executable on a computerfor performing a method of transcoding digital content, the methodcomprising the steps of: reading annotations to be used in a transcodingstep from a database; determining an annotation corresponding to thedigital content based on correlation between a layout of the digitalcontent and descriptions of the annotations; and transcoding the digitalcontent based on the annotation determined at the determining step.
 9. Acomputer-readable recording medium storing annotation data to be used ina transcoding process of digital content, wherein said annotation datais stored in annotation files that are prepared for units of digitalcontents, the annotation data including descriptions for the transcodingprocess, the descriptions being correlated with a layout of elements inthe digital contents; and wherein said annotation files are sorted basedon location information of the digital contents on a network.
 10. Thecomputer-readable recording medium according to claim 9, wherein thedescriptions in the annotation data are correlated with the layout ofthe elements in the digital contents by using XPath.
 11. Thecomputer-readable recording medium according to claim 9, wherein saidannotation files are sorted based on URLs (Uniform Resource Locators).12. The computer-readable recording medium according to claim 9, whereinthe annotation data include information for identifying an element inthe digital content for which a layout change is planned.
 13. A programproduct executable on a computer for performing a method of managingannotation data to be used for transcoding digital content, the methodcomprising the steps of: evaluating a correlation between elements inthe digital content and a description in the annotation data; andpresenting a interface to show a state of the correlation between thedigital content and the annotation data, based on evaluation resultsobtained by the evaluating step.
 14. The program product according toclaim 13, wherein said interface provides, for each element of thedigital content, a list for displaying whether the description of acorresponding annotation data is present.
 15. The program productaccording to claim 13, wherein said interface provides a displaycomponent on which a detailed correlation between the description of theannotation data and the elements in the digital content is displayed.16. The program product according to claim 13, wherein said interfaceprovides a display component for accepting an entry from a user andinteractively displaying a state of the annotation data corresponding tothe digital content based on the entry.
 17. The program productaccording to claim 13, wherein said interface provides a displaycomponent for editing the annotation data.